1. Field of the Invention
The present invention relates to a sintered magnesium-based composite material and a process for preparing the same.
2. Description of the Related Art
Magnesium alloys have attracted attention as light-weight high mechanical strength metals useful in connection with aircraft and space equipment and components and electronics equipment and components.
In the field of electronics equipment and components, mechanical parts for magnetic recording, particularly head arms, are often diecast from a magnesium alloy. The important characteristics of such a material when used to form head arms include (1) low density and (2) high mechanical strength. Particularly such material should have a high Young's modulus of elasticity. Magnesium is a good candidate for such head arm applications due to its low density; however magnesium has a low Young's modulus of elasticity. Therefore, if a magnesium alloy having an increased modulus of elasticity without experiencing a substantial change in its low density is provided, for making head arms the performance of magnetic recording operations may be improved by increasing the speed of movement of the head.
Known method of improving the modulus of elasticity of a magnesium alloy involves adding a very small amount of zirconium or rare earth metal to the alloy to prevent growth of the crystal grains of the magnesium however, only this provides a modulus of elasticity of only, about 4500 kgf/mm.sup.2 which is still too low for some applications.
In Japanese Unexamined Patent Publication (Kokai) No. 55-161495 published on Dec. 16, 1980, H. Inoue et al. disclose a vibrating plate for a sonic converter made of a fused alloy of magnesium and boron. Such fused or cast alloy of magnesium and boron, however, does not provide a uniform composition due to the difference between the densities of magnesium and boron, and therefore, does not provide the expected improved properties.
Sintering shape magnesium powders to obtain a shaped sintered body is also known, but such procedure does not provide bodies having a sufficient Young's modulus of elasticity.